I wonder if there was any reason to mimic a humans swing other than for ascetics? A simple flywheel or pneumatic propelled straight swing through the zone would be easier to implement and provide more power. Give it an optical sensor to align the bat position vertically and to time the swing. Then construct the whole contraption on an ATV chassis and you've got your new DH :)

Welllll since you all have beaten me to the "Bob, why did you post a video of Abe Nunez's swing?" joke, I think I'm gonna go with either "That looks like Jeremy Giambi practicing his baserunning!" OR "This is what Ben Grieve looked like before he met Jose Canseco"